Emma Watson has defended Kristen Stewart's fling with married director Rupert Sanders, behind the back of current boyfriend Robert Pattinson, claiming Kristen is “human” and that “everyone makes mistakes”.

The British actress, who co-starred with Rob in 'Harry Potter And The Goblet of Fire', commented on the affair in a new interview and claims people have the wrong idea about movie stars and that they're not as “perfect” as fans think.

“Those who criticised her are the same people that think that being rich and famous is like being covered in some kind of magic powder that makes life perfect,” she told Vanity Fair Italia.

“Nothing can go wrong in your wonderful world. For these people, Kristen deserves all the bad things that have been thrown at her because she had an amazing life and she ruined it."

Kristen and Emma were spotted hanging out at the Toronto Film Festival in September where they were both promoting movies and are clearly close friends. She claimed the treatment of Kristen, who admitted the affair with the father of two in a statement after photos of them kissing were published by Us Weekly in July, were unfair.

Emma Watson picks up the People's Choice Awards for her role in 'The Perks Of Being A Wallflower' in January (WENN)

Emma explained: “I thought that the media picked on her in a very horrible way. Kristen is human, just like everybody else, and she's so young. Everyone makes mistakes, everyone. It's not fair to consider them matters of public interest….”

The 'Twilight' actress hasn't talked about the fling publicly since her emotional statement made to People magazine, in which she said: "I'm deeply sorry for the hurt and embarrassment I've caused to those close to me and everyone this has affected. This momentary indiscretion has jeopardised the most important thing in my life, the person I love and respect the most, Rob. I love him, I love him, I'm so sorry."